This invention relates to an elevator control system for effecting the group supervision of a plurality of elevator cars by estimating presumed arrival time intervals of the elevator cars in response to a floor call or calls. More particularly, the invention concerns an elevator control system arranged to estimate a presumed arrival time interval of each elevator car at each floor of a building served by the elevator cars by predicting car suspending time intervals required for a passenger or passengers to get on the elevator car at a non-responding floor or floors and for the passenger or passengers to get off the elevator car at a forward floor or floors which is or are located in front of that floor at which the passenger or passengers has or have got on the elevator car, in a direction of travel of the elevator car.
Group supervisory elevator systems are arranged to be responsive to the registration of a floor call to select an elevator car most suitable for responding to that floor call on the basis of information required for the group supervision and to assign the floor call to the selected elevator car. Upon the assignment of a floor call, it is required to predict how a car suspending time interval will change due to a car call or calls on the elevator car in operation and a floor call or calls for that elevator car.
To this end, it has been already proposed to effect the predictions in accordance with a percentage destination of getting-on passengers to each floor. More specifically, a load on the elevator car or the number of passengers getting off the elevator car at each floor is predictively calculated by first preparing percentage destinations to forward floors with respect to passengers getting on the elevator car at each floor in each of the directions of travel of the elevator car, and then distributing a predicted number of getting-on passengers due to a floor call at each floor in each of the travel directions in accordance with the percentage destinations to the forward floors, and then effecting the subtraction at each of the forward floors in accordance with an associated one of the resulting distribution ratios.
In the prediction method as described above, it has been required to know data for the percentage destinations to the forward floors for each floor and for each travel direction and also to effect a calculation with respect to all the forward floors for each floor and for each direction resulting in the prolongation of a calculation time. As a result, an elevator car movement has been determined by disregarding a floor call or calls occurring in the calculation. This has resulted in a high possibility of preventing the elevator car from being assigned in comformity with the status quo.
Accordingly, it is an object of the present invention is to provide a new and improved elevator control system for accurately estimating car suspending time interval resulting from a car call or calls and a floor call or calls and capable of easily calculating a presumed arrival time interval of an elevator car at each floor of a building served by the elevator cars within a short data processing time interval.